The relative efficiency of aerocapture for interplanetary dust by the planets

Abstract

Numerical techniques have been applied to calculating the trajectories of interplanetary particles approaching the Earth, Venus and Saturn under the influence of gravitational and atmospheric drag forces. Particle capture cross-sections and orbital evolution and lifetimes have been calculated. In addition, the peak temperatures and pressures experienced by particles during aerobraking have been calculated in order to assess the relative importance of aerocapture and aerofragmentation capture. Results suggest that the differing masses, atmospheric profiles and solar distances of the planets result in significantly different populations of captured orbital material. For the Earth, the population of natural orbital material will show a steeper mass distribution than does the interplanetary population due to the preferential capture of smaller particles. Venus will have only a small population of orbital particles as its small atmospheric scale height results in very small capture probabilities. Saturn will have a significant population of captured material, but with a broadly interplanetary mass distribution due to the small mass dependence of the capture probability.